1. Field of the Invention
The present invention relates to a venetian blind assembly machine ladder guide mechanism.
2. Description of the Prior Art
Various types of venetian blind assembly machines are known in which punched and cut slats are fed into a so-called "lacing section", in which the slats are fed into the gaps between the vertical cords of a venetian blind cord ladder and above the rungs thereof. Some ladders have double rungs, and the slats may sometimes be fed between the upper and lower cords of such a double rung.
An example of such a machine is shown in EP-B-133759. In this machine, two or more ladder support guides are provided to guide each ladder cord accurately to the correct position to receive the slats when they arrive. The positioning must be very exact as the slats are only provided with a very small "target", by the ladder, particularly with double rung ladders. Of course such a machine is relatively expensive and needs to be capable of being used for blinds of different sizes and types.
U.S. Pat. No. 4,526,300 discloses a ladder support guide change mechanism for a venetian blind assembly machine, said mechanism comprising a ladder support guiding means and a ladder support advancing means associated with said ladder support guiding means.
One of the major problems of known venetian blind assembly machines is that a rather long time is taken to set up different ladder support guides for a change of blind to be manufactured.